The invention relates generally to vehicle drawn trailers, and more particularly to an auxiliary extension mechanism devised as a kit for use with boat or other types of trailers.
As any boat enthusiast knows who trails his boat to a ramp or shore for launching, there are severe limitations to the conventional boat trailers which prevent the enthusiast from launching or retrieving his boat in shallow water or at low tide or in the event that his boat has a deep keel, such as, for example, in the case of sailboats which are provided with relatively deep fixed keels. While these adverse conditions are not always present when the boater wishes to enjoy the pleasures afforded by boating or sailing, they nevertheless may limit his full use of his or her boat.
There have been attempts in the prior art to minimize the loss of full use of boats for the operator by arranging boat trailer tongues with extension devices which permit the operator to elongate the tongue so that the vehicle towing the trailer need not drive his vehicle too close to or into the water's edge, and yet be able to move the trailer further out into the water thereby avoiding inadvertent scraping of the bottom of the launch site by his boat keel.
Another disadvantage with some of the conventional tongue and extension mechanisms is that these extensions are integrated into and are a part of the tongue itself, and thereby become too expensive for the average boater. These arrangements require that those boaters who presently own and operate conventional boat trailers must discard their boat trailer and purchase a new one in the event that they need the same only occasionally. In any event, the trailers of the prior art require an expensive apparatus that is not necessarily utilized for all boating opportunities for which the enthusiast has.
Some examples of prior art structures are discussed hereafter.
In the prior art, a boat trailer extension tongue is disclosed in U.S. Pat. No. 3,984,121 to Dobosi wherein an extension having a rack gear is arranged to telescope within the tubular frame of the boat trailer in order to lengthen or shorten the total length of the tongue. In this arrangement, the extension and associated structure is integrated with a boat trailer thereby requiring the operator to purchase the boat trailer with this accessory whether he needs it or not. Similarly, the extension device in U.S. Pat. No. 4,169,611 to Smith et al. is a dedicated piece of structure which is integrally incorporated into the boat trailer tongue. The same disadvantage is also generally found with the trailer hitch arrangement disclosed in U.S. Pat. No. 3,326,573 to Neitzey, Jr.
The prior art also includes disclosures with respect to extending hitches between draft vehicles and a driving vehicle. Examples of such prior art are disclosed in U.S. Pat. Nos. 2,693,368 to Petron and 2,894,766 to Habriga. In each of such disclosures, the rack gears involved are integral parts of the hitch structure so that undue expense must be a prospect in the event that extension of a hitch is required for those seldom times where its use is necessary. In U.S. Pat. No. 3,446,518 to Dodgson et al., a telescoping hitch link is disclosed as having a locking rod for locking the link members when extended.